28o ASTER FAMILY 



b. Leaves mostly alternate, only the lower oppo- 

 site 



( 1 ) Leaves linear or lance-linear ; perennial H. orgydlis 



(2) Leaves ovate; annual 



(a) Leaves entire or nearly so; bracts of the 



involucre lanceolate, gray-hairy H. petioldris 



(b) Leaves toothed; bracts oblong to ovate, 



long-pointed, hairy and ciliate H. dnnuus 



2. Disk yellow 



a. Leaves opposite ; stems rough and bristly, 1-3 



ft. high H. pumilus 



b. Some of the upper leaves alternate 



(1) Stem leaves rough and somewhat hairy H. Maximilidni 



(2) Stem smooth, often glaucous 



(a) Leaves mostly sharply toothed, hairy 



beneath H. grosse-s-errdtus 



(b) Leaves entire or finely toothed, not hairy 



beneath H. Nuttdllii 



HELIOPSIS Persoon 1807 OX-EYE 

 (Gr., helios, sun, opsis, likeness) 



Heads with yellow pistillate ray-flowers, rays persisting, disk-flowers 

 yellow, perfect, achenes 3-4-angled, pappus a short, toothed crown, or of 1-3 

 awns ; receptacle convex to conic, with chaff, involucre hemispheric, the 

 bracts imbricated in 2-3 rows ; heads solitary, terminal and axillary ; leaves 

 opposite, simple, perennial. 

 Stems 2-5 ft. high ; leaves ovate or lance-ovate, toothed, 



2-5 in. long ; rays an inch long or more H. scdbra. 



HIERACIUM Linne 1753 HAWKWEED 

 (Gr. hierax, hawk) 



Heads with yellow, orange or red perfect strap-flowers, achenes ob- 

 long to cylindric, not beaked, 10-15-ribbed, round or 4-5-angled, pappus 

 of brown or brownish hair-like bristles ; receptacle flat, without chaff, in- 

 volucre bell-shaped to cylindric, the bracts in 1-3 rows, often with smaller 

 basal ones ; heads solitary or in corymbs or panicles ; leaves alternate or 

 basal, entire to toothed or lobed ; perennial. 



1. Bracts of the involucre in 2-4 rows; stems leafy 



a. Leaves, at least the upper, clasping; involucre 



hairy H. canadense 



b. Leaves not clasping ; involucre smooth H. umbelldtum 



